Splitting by Season


This analysis groups fish by season as well as decade to determine significance.
## Atlantic Cod
Original Cod data:

Transformed Cod data:

Cod table by decade and season and linear model:

##           1990s    2000s    2010s    2020s
## SUMMER 3.069992 2.963709 3.106042       NA
## FALL         NA       NA       NA       NA
## WINTER 3.052689 3.147139       NA       NA
## SPRING 3.058870 3.044934 3.044054 3.048327

## 
## Call:
## lm(formula = log(INDWT) ~ log(LENGTH) * decade + log(LENGTH) * 
##     SEASON)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -4.6291 -0.0701 -0.0008  0.0690  2.2164 
## 
## Coefficients:
##                            Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)              -12.044000   0.015298 -787.279  < 2e-16 ***
## log(LENGTH)                3.140433   0.003958  793.369  < 2e-16 ***
## decade2000s               -0.087804   0.015791   -5.560 2.71e-08 ***
## decade2010s               -0.014461   0.017471   -0.828    0.408    
## decade2020s                0.028607   0.030762    0.930    0.352    
## SEASONSPRING               0.341293   0.011944   28.574  < 2e-16 ***
## SEASONSUMMER               0.273456   0.026610   10.276  < 2e-16 ***
## SEASONWINTER               0.087130   0.021747    4.007 6.17e-05 ***
## log(LENGTH):decade2000s    0.019589   0.004070    4.813 1.49e-06 ***
## log(LENGTH):decade2010s    0.002659   0.004514    0.589    0.556    
## log(LENGTH):decade2020s   -0.001466   0.008096   -0.181    0.856    
## log(LENGTH):SEASONSPRING  -0.102321   0.003113  -32.865  < 2e-16 ***
## log(LENGTH):SEASONSUMMER  -0.070486   0.006911  -10.199  < 2e-16 ***
## log(LENGTH):SEASONWINTER  -0.029030   0.005621   -5.164 2.43e-07 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.1296 on 41213 degrees of freedom
## Multiple R-squared:  0.9914, Adjusted R-squared:  0.9914 
## F-statistic: 3.665e+05 on 13 and 41213 DF,  p-value: < 2.2e-16


American Plaice


Transformed American plaice data:

American plaice table by decade and season and linear model:

##           1990s    2000s    2010s    2020s
## SUMMER 3.181419 3.224220       NA       NA
## WINTER 3.259863 3.401977       NA       NA
## SPRING 3.312532 3.350355 3.291251 3.271513
## 
## Call:
## lm(formula = log(plaice$INDWT) ~ log(plaice$LENGTH) * plaice$decade + 
##     log(plaice$LENGTH) * plaice$SEASON)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.00273 -0.08294 -0.00461  0.07729  2.67662 
## 
## Coefficients:
##                                          Estimate Std. Error  t value Pr(>|t|)
## (Intercept)                            -1.278e+01  1.484e-02 -861.082  < 2e-16
## log(plaice$LENGTH)                      3.314e+00  4.475e-03  740.685  < 2e-16
## plaice$decade2000s                     -1.988e-01  1.760e-02  -11.298  < 2e-16
## plaice$decade2010s                     -1.187e-02  1.656e-02   -0.717   0.4734
## plaice$decade2020s                      1.193e-02  2.659e-02    0.449   0.6538
## plaice$SEASONSPRING                     2.166e-02  1.198e-02    1.808   0.0707
## plaice$SEASONSUMMER                     3.859e-01  2.864e-02   13.477  < 2e-16
## plaice$SEASONWINTER                     1.570e-01  9.777e-02    1.605   0.1084
## log(plaice$LENGTH):plaice$decade2000s   4.103e-02  5.319e-03    7.714 1.25e-14
## log(plaice$LENGTH):plaice$decade2010s   5.597e-04  4.996e-03    0.112   0.9108
## log(plaice$LENGTH):plaice$decade2020s   2.928e-04  8.035e-03    0.036   0.9709
## log(plaice$LENGTH):plaice$SEASONSPRING -1.644e-02  3.641e-03   -4.515 6.35e-06
## log(plaice$LENGTH):plaice$SEASONSUMMER -1.242e-01  8.663e-03  -14.336  < 2e-16
## log(plaice$LENGTH):plaice$SEASONWINTER -3.756e-02  2.717e-02   -1.382   0.1669
##                                           
## (Intercept)                            ***
## log(plaice$LENGTH)                     ***
## plaice$decade2000s                     ***
## plaice$decade2010s                        
## plaice$decade2020s                        
## plaice$SEASONSPRING                    .  
## plaice$SEASONSUMMER                    ***
## plaice$SEASONWINTER                       
## log(plaice$LENGTH):plaice$decade2000s  ***
## log(plaice$LENGTH):plaice$decade2010s     
## log(plaice$LENGTH):plaice$decade2020s     
## log(plaice$LENGTH):plaice$SEASONSPRING ***
## log(plaice$LENGTH):plaice$SEASONSUMMER ***
## log(plaice$LENGTH):plaice$SEASONWINTER    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.1329 on 42945 degrees of freedom
## Multiple R-squared:  0.9882, Adjusted R-squared:  0.9882 
## F-statistic: 2.769e+05 on 13 and 42945 DF,  p-value: < 2.2e-16


Atlantic Herring


Transformed Cod data:

Atlantic herring table by decade and season and linear model:

##           1990s   2000s    2010s    2020s
## SUMMER 3.162187      NA 3.110690 3.205235
## FALL         NA      NA       NA       NA
## WINTER 2.848033 3.06000       NA       NA
## SPRING 3.023497 3.18669 3.144721 3.133027
## 
## Call:
## lm(formula = log(herring$INDWT) ~ log(herring$LENGTH) * herring$decade + 
##     log(herring$LENGTH) * herring$SEASON)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2.5356 -0.0755  0.0062  0.0843  7.3503 
## 
## Coefficients:
##                                            Estimate Std. Error  t value
## (Intercept)                              -11.303040   0.019342 -584.380
## log(herring$LENGTH)                        2.901161   0.006140  472.535
## herring$decade2000s                       -0.557109   0.019424  -28.681
## herring$decade2010s                       -0.237912   0.019985  -11.904
## herring$decade2020s                        0.120946   0.065058    1.859
## herring$SEASONSPRING                      -0.491803   0.014503  -33.911
## herring$SEASONSUMMER                      -0.751938   0.043119  -17.439
## herring$SEASONWINTER                      -0.007619   0.034600   -0.220
## log(herring$LENGTH):herring$decade2000s    0.191790   0.006171   31.082
## log(herring$LENGTH):herring$decade2010s    0.082538   0.006384   12.929
## log(herring$LENGTH):herring$decade2020s   -0.023295   0.020471   -1.138
## log(herring$LENGTH):herring$SEASONSPRING   0.126567   0.004651   27.215
## log(herring$LENGTH):herring$SEASONSUMMER   0.260470   0.013549   19.224
## log(herring$LENGTH):herring$SEASONWINTER  -0.037384   0.010998   -3.399
##                                          Pr(>|t|)    
## (Intercept)                               < 2e-16 ***
## log(herring$LENGTH)                       < 2e-16 ***
## herring$decade2000s                       < 2e-16 ***
## herring$decade2010s                       < 2e-16 ***
## herring$decade2020s                      0.063023 .  
## herring$SEASONSPRING                      < 2e-16 ***
## herring$SEASONSUMMER                      < 2e-16 ***
## herring$SEASONWINTER                     0.825704    
## log(herring$LENGTH):herring$decade2000s   < 2e-16 ***
## log(herring$LENGTH):herring$decade2010s   < 2e-16 ***
## log(herring$LENGTH):herring$decade2020s  0.255154    
## log(herring$LENGTH):herring$SEASONSPRING  < 2e-16 ***
## log(herring$LENGTH):herring$SEASONSUMMER  < 2e-16 ***
## log(herring$LENGTH):herring$SEASONWINTER 0.000676 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.1338 on 102990 degrees of freedom
## Multiple R-squared:  0.9566, Adjusted R-squared:  0.9566 
## F-statistic: 1.745e+05 on 13 and 102990 DF,  p-value: < 2.2e-16


Spiny Dogfish


Transformed dogfish data:

Spiny dogfish table by decade and season and linear model:

##           1990s    2000s    2010s    2020s
## SUMMER 3.124308       NA 3.267771       NA
## FALL         NA       NA       NA       NA
## WINTER 3.123125 3.195706       NA       NA
## SPRING 3.161359 3.217659 3.152926 3.065457
## 
## Call:
## lm(formula = log(dogfish$INDWT) ~ log(dogfish$LENGTH) * dogfish$decade + 
##     log(dogfish$LENGTH) * dogfish$SEASON)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -4.0963 -0.0885 -0.0044  0.0842  1.7453 
## 
## Coefficients:
##                                            Estimate Std. Error  t value
## (Intercept)                              -12.626413   0.019436 -649.636
## log(dogfish$LENGTH)                        3.048020   0.004633  657.862
## dogfish$decade2000s                       -0.236000   0.019425  -12.149
## dogfish$decade2010s                        0.006186   0.021964    0.282
## dogfish$decade2020s                        0.390083   0.041241    9.459
## dogfish$SEASONSPRING                      -0.495222   0.019276  -25.691
## dogfish$SEASONSUMMER                      -0.309360   0.038695   -7.995
## dogfish$SEASONWINTER                      -0.419109   0.024920  -16.818
## log(dogfish$LENGTH):dogfish$decade2000s    0.058180   0.004598   12.654
## log(dogfish$LENGTH):dogfish$decade2010s   -0.004884   0.005269   -0.927
## log(dogfish$LENGTH):dogfish$decade2020s   -0.104144   0.009905  -10.514
## log(dogfish$LENGTH):dogfish$SEASONSPRING   0.112350   0.004596   24.445
## log(dogfish$LENGTH):dogfish$SEASONSUMMER   0.080206   0.009232    8.688
## log(dogfish$LENGTH):dogfish$SEASONWINTER   0.083765   0.005917   14.157
##                                          Pr(>|t|)    
## (Intercept)                               < 2e-16 ***
## log(dogfish$LENGTH)                       < 2e-16 ***
## dogfish$decade2000s                       < 2e-16 ***
## dogfish$decade2010s                         0.778    
## dogfish$decade2020s                       < 2e-16 ***
## dogfish$SEASONSPRING                      < 2e-16 ***
## dogfish$SEASONSUMMER                     1.32e-15 ***
## dogfish$SEASONWINTER                      < 2e-16 ***
## log(dogfish$LENGTH):dogfish$decade2000s   < 2e-16 ***
## log(dogfish$LENGTH):dogfish$decade2010s     0.354    
## log(dogfish$LENGTH):dogfish$decade2020s   < 2e-16 ***
## log(dogfish$LENGTH):dogfish$SEASONSPRING  < 2e-16 ***
## log(dogfish$LENGTH):dogfish$SEASONSUMMER  < 2e-16 ***
## log(dogfish$LENGTH):dogfish$SEASONWINTER  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.1321 on 63035 degrees of freedom
## Multiple R-squared:  0.9779, Adjusted R-squared:  0.9779 
## F-statistic: 2.146e+05 on 13 and 63035 DF,  p-value: < 2.2e-16